W12 L2 - Mendelian Genetics and Evolution - Lecture 8: Linkage

Flashcards covering key concepts from Lecture 8 on linkage in Mendelian Genetics and Evolution.

What happens when alleles are located close together on the same chromosome?

They are likely to be inherited together more often than expected by chance, an occurrence termed linkage.

Define a haplotype?

All the alleles that are linked together on a single copy of the chromosome.

How is genetic distance measured?

By the proportion of recombinant offspring versus offspring that inherit the parental haplotypes.

What is a linkage map?

A map showing the position of genes relative to each other in terms of recombination frequency, not physical base pair distance.

What is the purpose of a three-point test cross?

To measure the genetic distance between three genes, allowing for the determination of gene order on a chromosome.

In a three-point test cross, which offspring are the least common?

Offspring resulting from a double recombination event, where the gene in the middle of the trio is swapped.

How do you identify a gene in the middle of a trio?

The gene that has switched between the two least common offspring combinations

What is the relationship between recombination frequency and genetic distance?

The greater the recombination frequency between two genes, the greater the genetic distance between them.

When calculating recombination frequency in a three-point cross, what must be considered?

Both single and double recombinant offspring must be included in the calculation.

What determines the likelihood of the recombination?

The distance between them. The larger the distance, the bigger the likelihood.